Hello all,

Can anybody tell me if there is substitute or modern type of replacement for a 302 bulb used in this 601 model Stromberg Carlson radio .

Thanks in advance

Vic

#302 Miniature Bulb Ba15d Base - 28 Volt 0.17 Amp 4.76 Watt G5 Double Contact Bayonet (BA15d) Base, MSCP 3.0, C-2F Filament Design, 1.38" (35.1mm) Maximum Overall Length (M.O.L.), 0.63" (16mm) Maximum Outer Diameter (M.O.D.). 0.69" (17.5mm) Light Center Length (L.C.L.) 500 Average Rated Hours.

How about this? https://www.interlight.biz/light-bulb/WAMCO-WL301

GTC,

Got some info on it , that one is the wrong one. It can be a 1941 or 302, looks like a large light globe.

Base Edison big E27 = 27 mm

Filament If 0.3 Ampere / Series, AC/DC /

Description 300mA current stabiliser for voltage drops from 80 to 200.

Text in other languages (may differ)
Dimensions (WHD)
incl. pins / tip 50 x 138 x mm / 1.97 x 5.43 x inch.

that one is the wrong one

That info on #302 came from Bulbtown's site, and others. Probably all copying from each other.

Filament If 0.3 Ampere

What voltage?

So it's a baretter?

Yes, that's right, a barretta or ballast tube.

I posted here on the Forums a pdf spec sheets for that particular barretta a while back:

https://vintage-radio.com.au/default.asp?f=1&th=1014&offset=2

Osram 301, 302, 303 and 304 Barrettas

Yes it is a voltage stabiliser,

240v . I went a local lamp supplier because he carries vintage bulbs, but he couldn't help me. But he suggested using a 100w light bulb to test things.

So the light bulb lights up and the set comes to life but needs more work to get radio stations . The audio section is fine. I can only presume the 302 doesn't light up so bright . So can I leave the light bulb in or source a replacement 302 bulb?

Any ideas appreciated .

Cheers
Vic

I should have cottoned on to barretter when you said 27 mm base.

The barretter is a current limiter, not a light bulb as such. Its function is to protect series-connected valve filaments against voltage rises. If the barretter is open circuit, then none of the filaments will light up. It needs to have the same nominal current rating as the valves themselves, in your case 300mA.

Your 100 watt bulb will draw about 415mA at 240 volts, so its filament has a resistance of 576 ohms. A light bulb is not a direct substitute for a barretter because it doesn't have the ability to limit current as the voltage rises.

What is the problem with your existing barretter?

Brad: the PDF link in post #6 above appears to be broken.

- oops, deleted -

All fixed.

Hi GTC,

It doesn't have one. So I need to find one, hence the question can it be substituted.

In hindsight I should have walked away from this one, because I have to construct a dial coupling because the original is also non existent.

Cheers
Vic

It doesn't have one . So I need to find one

Okay, that certainly 'shines a new light' on your problem.

Here you go. Grab one while it's still available:

http://www.ebay.co.uk/itm/302-MARCONI-BARRETTER-TUBES-VALVES-NEW-1-PC-/390335413201

Thanks GTC

I was looking locally but I have purchased the remaining 4 from the listing you provided.

Thanks again
Vic

Always happy to help where possible.

I hope that UK seller knows how to pack glass for a long trip.

I hope that UK seller knows how to pack glass for a long trip.

And for our posties and courier drivers...